1. Field of the Invention
The present invention is generally in the field of electronic devices and systems. More particularly, the present invention is in the field of delivery of power to electronic devices and systems.
2. Background Art
In several applications in integrated circuit design, systems require a combination of analog circuits and digital switching devices. Large input signal amplitude in analog circuit design is desired because it maximizes the signal-to-noise ratio (SNR) and reduces the power consumption. For this purpose a high supply voltage is required for the circuit to accommodate the high input signal. However, when using the high supply voltage in the whole system one of the major drawbacks is that the CMOS logic has to operate at high supply voltage as well.
High-voltage-tolerance CMOS devices have a high breakdown voltage but they also have slow switching characteristics. For example, in 65 nm or 40 nm standard CMOS technology, there are two types of CMOS devices: thick-gate-oxide devices with high supply tolerance of 2.5V and thin-gate-oxide devices with a supply voltage tolerance of 1V. While the thick-gate device has a higher voltage tolerance the switching speed is 10 times slower than that of thin-gate devices. Thus there is a trade-off in speed and SNR when choosing thick-gate or thin-gate devices for the system.
Thus, there is a need to overcome the drawbacks and deficiencies in the art by providing an integrated solution which allows a high supply voltage for analog circuits such as amplifiers to achieve good SNR, while allowing for the use of low voltage devices, such as fast thin-gate-oxide devices for CMOS switching circuits.